Abstract
The article deals with analysis of the causes of intersymbol interference and interchannel interference. It is indicated that physically unrealizable orthogonal bases are used to describe systems and signals. The considered interference occurs due to the loss of orthogonality by the coordinate signals of the bases. Known methods for obtaining systems of orthogonal functions do not allow the formation of a coordinate basis corresponding to physically feasible systems and signals. It is proposed to use equidistant biased impulse characteristics of physically realizable linear systems as basic signals. An orthogonalization method based on determining the weight of orthogonality is described. It is shown that the resulting basis is quasi-orthogonal. It is determined that the conversion of the standart low-pass prototype filter into the filters of channel-forming equipment does not change the conditions of orthogonality. Structural schemes of a modulator and a demodulator of two-dimensional signals are proposed, based on the developed method of orthogonalization.
Highlights
Consider the causes of intersymbol interference (ISI) and inter-channel interference (ICI) and the relationship between them
The reason for the ICI is the penetration on the output of CAE of one signal channel of the signals of the channels due to the overlap in frequency of the amplitude-frequency characteristics (AFC) of the filters of the channels of CAE
That carry information, is a linear combination of signals of the coordinate orthogonal basis. From this point of view, the ISI is a consequence of the waste of orthogonality by the signals by means of which message symbols are transmitted; and ICI arise as a result of the fact that the signals transmitted in adjacent communication channels, due to non-ideal frequency response of the channels, stops to be orthogonal
Summary
The chracteristic of modern digital information transmission systems (ITS) is that the levels of intersymbol interference (ISI) and inter-channel interference (ICI) is higher, than the noise level in the communication channel. There is a scientific problem: on the one hand, the physical feasibility of information transmission systems imposes restrictions on the choice of the system of orthogonal functions required to describe signals; on the other hand, the existing theory of orthogonal series and integral transformations does not allow the creation of the indicated system of orthogonal functions. The solution to the problem of simultaneously reducing the levels of ISI and ICI, and, increasing the noise immunity and efficiency of ITS is associated with the development of new methods for describing signals and information transmission systems. These new methods should not lead to a significant complication of ITS
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
